Method of making sets of artificial teeth



Oct. 7, 1924. v 1,511,161 v J. M. BUCHANAN METHOD OF MAKING SETS 0FARTIFICIAL TEETH Filed March 4, 1924 WITNESSES l/VVEN TOR JMEJJCM/Zd)?l1 TTORNE Y S Patented Oct. 7, 1924.

JOSEPH M. BUCHANAN, OF FREEPORI, NEW YORK.

METHOD OF IMAKING- SETS OF ARTIFICIAL TEETH.

Application filed March 4, 1924.

To all whom it may concern:

Be it known that I, JOSEPH M. BU- GHANAN, a citizen of Canada, andresident of Freeport, in the county of Nassau and State of New York,have invented a new and Improved Method of Making Sets of ArtificialTeeth, of which the following is full, clear, and exact description.

This invention relates to mechanical dentistry and has particularreference to an improved method or process of making an integral set ofartificial teeth and supporting plate.

Among the objects of the invention is to provide a method of making acombined set of teeth and plate of one piece of plastic material such asporcelain, so that the finished plate shall have a size and form toprecisely fit the mouth cavity and without a permanently attached sheetor plate of metal.

With the foregoing and other objects in view the invention comprises orrelates to a series of steps substantially as hereinafter more fullydescribed and claimed, and I wish it to be understood, however, that thespirit of the invention is to be interpreted sufficiently broadly toembody certain variations in any of said steps.

For the purpose of illustrating a practical embodiment of the inventionreference is had to the accompanying drawings, in which like referencecharacters designate the same parts in the severalviews, and in whichFigure 1 is a perspective view indicating a conventional form of meansfor taking the impression of the mouth cavity.

Fig. 2 is a vertical transverse section of the same on the line 2-2.

Fig. 3 is a similar view illustrating the next step of the process.

Fig. 4 is a view indicating a succeeding step, namely the formation ofthe positive cast or model.

Fig. 5 is a cross sectional view of the model detached from the deviceas shown in Fig. 3.

Fig. 6 indicates the next step in the process in the applying of a sheetof metal or the like to the positive cast.

Fig. 7 is a perspective view of the plate shown in Fig. 6 ready for themolding thereon of the plastic material to form the set of teeth andintegral plate; and

Fig. 8 is a vertical transverse section Serial No. 696,859.

through said plate and metal base on a plane corresponding to the lines88 of Fig; 7.

Referring now more particularly to the drawings 1 show in Fig. 1 theprocess and means for forming an impression of the mouth cavity to befitted. Ordinarily this process involves the use of a metal shell 10having a shank 11 and adapted to contain a body or mass of plasticmaterial 12 of any suitable nature which after the impression is made isadapted to harden sufiiciently to serve to reproduce other deviceshaving forms corresponding to that of the mouth cavity. For convenienceof this description l shall refer to this member 12 as the negativecast.

While the negative cast is still supported in the shell 10 and therebyheld sufiiciently firmly for this purpose, the surface 12 thereof,constituting a counterpart of they mouth cavity, is filled or coatedwith a thin layer 13 of some suitable plastic material such as paint,varnish, shellac or the like of substantially uniform thickness.

With the filled negative cast as shown in Fig. 3 thus provided, it isused as a mold for a positive cast or mold 14 formed therein shown inFig. 4. This positive cast may be made of plaster of Paris or any othersuitable plastic material having a fair degree of rigidity when set. Thepositive cast 14, shown detached in Fig. 5, is in the next step of theprocess turned over and has applied to its active surface 14 a layer ofsome suitable refractory metal 15, such as platinum or its equivalent.The cast 14 as formed is smaller than the mouth cavity by the thicknessof the filler 13. By applying the metal coating of a thickness equal tothe thick: ness of the filler, or in other words by making the filler ofa thickness corresponding to that of the metal to be used on the posi'tive cast, I produce the outer surface 15 of the plate 15 to constitutean exact counterpart of the mouth cavity. This plate 15 is then usedeither detached or in connection with the positive cast 14 supporting itas a base upon which is molded the plate 16 and teeth 17 integraltherewith all from a sin gle mass or body of plastic material such asporcelain. The portion of the plate 16 representing the gum may betinted as is well known in the art either before or after the bakingthereof. With the mass of teeth and plate 16 attached thereto stillsupported upon the plate 15 it is subjected to a suitable baking processand thereafter the platinum 1.5 is stripped or otherwise removed fromthe finished plate 16. The surface of the plate formed in contact Withthe surface 15 of the platinum Will then be precisely of the size andform of the mouth cavity. The platinum may be used repeatedly as manytimes as may be desired inasmuch as it is not employed as a permanentpart of the teeth or plate.

I'claim:

The herein described method of making artificial teeth which comprisesthe following steps: (1) the making of a negative cast bearing an exactimpression of the mouth cavity; the coating of the active surface ofsaid negative cast with a thin filler of temporaryplastic material ofuniform thickness producing thereby a filled negative cast; (3) forminga positive cast or model in said filled negative cast; (4) forming uponsaid positive cast a layer of refractory metal of substantially thethickness of the filler applied to the negativeeast, thereby producing asurface the exact counterpart of the mouth cavity; (5) then mouldinguponsaid metal surface a set of teeth and attached plate;- (6) baking saidteeth and plate While supported upon said metal surface, and finallyremoving the metal from the baked teeth and plate.

' JOSEPH M. BUCHANAN;

